Recent Ruins / Catalogue / Metal
Knob and lock finishes
| Period range | 1860-1940 |
|---|---|
| Usual fabric | Brass, bronze, nickel plate over brass, japanned steel |
| Usual form | Rosettes, escutcheons, rim and mortice lock cases, strike plates |
| Wear to expect | Plating worn to the base metal, lacquer yellowing, japanning flaking |
Patina is metal that has changed. Plating loss is metal that has gone. They look similar in a dim yard and behave nothing alike.
What it is
Most decorative hardware is a base of brass or bronze, sometimes finished bright, sometimes plated. Nickel plate over brass gives a cool grey-white that was common in bathrooms and kitchens. Japanned steel is a black baked finish over pressed steel, used for utility hardware and for lock cases that were never meant to be seen. Rim locks mount on the face of the door; mortice locks sit inside it.
How to tell age
Fixing method dates a rosette faster than its pattern. Early rosettes are threaded or pinned; later ones are pressed and screwed through visible holes. Pressed-steel backplates with a thin stamped pattern are later than cast ones with a modelled back. Lock cases with a maker's mark cast into the case are generally earlier than those with a stamped applied label.
What commonly fails
Nickel plate wears through at every point a hand touches, exposing brass that then oxidises darker than the surrounding plate, giving the blotched look that no amount of polishing corrects. Old lacquer yellows and then flakes in patches. Japanning chips from the edges and the exposed steel rusts under the remaining film.
What to check before fitting
Decide before you buy whether you want the finish uniform or honest, because stripping plate and stripping lacquer are different jobs with different outcomes. Check that a rosette pair actually match on the back as well as the front. On a lock, work the bolt and the follower by hand through the full throw before judging anything about the case.